As sea levels continue to rise with accelerating climate change, experts say coastal wildlife – from shorebirds to sea turtles — are losing crucial nesting and feeding grounds. This has put many species at risk of population decline or worse.
Effects on Coastal Species
Global warming presents multiple threats, including rising sea levels, redrawing coastlines and whittling away vital habitats. Dr. Alastair Harborne, a marine biologist from Florida International University, said coastlines are a crucial habitat for many creatures.
“Their loss makes life very tough for the wildlife that depends upon them, and indeed for other ecosystems in general,” he said.
These include sea turtles, whose nesting areas have been shrinking, among a longer list of iconic species under threat.
“As the seas rise, beaches are narrowing, leaving turtles with fewer places to lay their egg,” said Harborne.
Where sea turtles lack adequate nesting grounds, their survival is in jeopardy.
Shorebirds are also very susceptible to rising seas. They rely on the wetlands and beaches along coasts for nesting and feeding. With rising sea levels, the encroaching water gets washed over this habitat.
“The habitat that birds use, like mangroves and beaches, is getting squeezed out,” said Harborne. Migratory shorebirds might find it impossible to get areas sufficiently large to rest and refuel along journeys.
The Ripple Effect on Ecosystems
The decline in habitat is of concern, but there are even broader possible impacts arising from rising sea levels. The coastal systems tend to be highly interlinked; thus, disturbances in one part become magnified into causing broad impacts across other parts. For example, there can be significant changes to the shallow-water food webs. Harborne said, “Large fish would remain inshore waters with higher levels.”
“It’s as if the tide is permanently high,” he described, which could allow predator fish to stay in the area and potentially unbalance an entire food web.
As the sea level rises, wetland habitats along coasts will increasingly become subject to saltwater intrusion, habitat loss, and ecosystem degradation. This trend already threatens wetland ecosystems in the Florida Everglades. One of these studies, conducted by FIU’s Institute of Environment postdoctoral associate Shimelis Dessu, show how salinity levels increase with the decrease of freshwater inflow and increased sea levels, which threaten species dependent on freshwater ecosystems.
The study emphasizes that “the impact per unit volume of inflow is significantly higher in the dry season in preventing high salinity and marine-derived nutrient levels.” Without the proper management of freshwater, higher sea levels will continue their damaging effects on wetlands areas of the coast, increasing pressure further on already vulnerable species.
Rising sea levels also affect the behavior of marine species. Large predatory fish that would typically retreat to deeper waters may now remain in shallow coastal areas for extended periods due to the higher water levels caused by sea level rise.
This prolonged stay could upset the delicate balance of coastal ecosystems.
“Larger fish staying inshore for longer can over-predate on smaller species, leading to disruptions in the food web,” Harborne said.
The behavior changes seen in marine species are one of the many unintended consequences of sea-level rise, affecting individual species and broader ecosystems.
Conservation Steps and Public Action
Meanwhile, in response to these threats, conservationists are putting an onslaught of efforts into protecting the ecosystems of the coasts. Restoration activities in the Florida Keys are helping to rehabilitate degraded reefs by cultivating small corals in nurseries and transplanting them onto degraded reefs.
“Our focus is on increasing coral cover and complexity,” Harborne said. “These efforts are vital to the health of Florida’s reefs, which support wildlife and the economy.”
Marine reserves and protected areas are another crucial tool in wildlife conservation. These zones serve as sanctuaries for threatened species, and fishing and coastal development are circumscribed.
“Coral reefs support not just wildlife but also tourism, fishing, and storm protection,” said Harborne. Conservation is vital to both ecological and economic sustainability.
These buy time, but they can’t stem the tide. The only genuinely long-term solution will be to tackle climate change itself. Global reductions in carbon emissions are crucial to reducing the rate of sea level rise and offering any hope for survival for species dependent on coastlines.
“Without action on climate change, conservation is merely a short-term fix,” warned Harborne.
The public also has a role to play in the support of such programs for conservation, he said. Small moves in mitigating plastic waste and promoting sustainable tourism can go a long way. More importantly, people can advocate for more robust local, national, and international environmental policies.
For people in South Florida, the present effects of rising impacts, ranging from frequent king tide flooding to saltwater intrusion in freshwater supplies, have become familiar.
“People are beginning to realize the true costs of sea-level rise,” said Harborne. “As this financial burden of coastal protection mounts, so does the urgency to act.”
